/Engine/Plugins/Runtime/MassEntity/Source/MassEntity/Public/MassEntityQuery.h
Checks if any of ValidArchetypes has any entities. Note that the function is not const because calling it can result in re-caching of ValidArchetypes
"true" if any of the ValidArchetypes has any entities, "false" otherwise
bool HasMatchingEntities ( [FMassEntityManager](API\Plugins\MassEntity\FMassEntityManager) & InEntityManager )